Today, it is common for communication networks other than the public switched telephone network (PSTN) to provide telephony services. For example, such as the Internet and world wide web now support such services. Notably, however, today's broadband carriers of residential transmissions--e.g. cable television networks--do not support telephone services. One reason for this is that such networks have been designed basically as alternatives to broadcast television. Consequently, cable network equipment and distribution facilities traditionally have been structured primarily to deliver television signals unidirectionally from a "head end", where television signals are received and assembled for delivery, to residential customers.
In some cable networks, data is carried "upstream" from customers to the head end; for example, data indicating acceptance of pay-per-view programs and requiring changes of decoding parameters at decoder equipment located at customer sites, etc. However, this involves low usage/low data rate activities over a channel shared by all customer units receiving service over common branch and trunk lines; typically, in an operation much like that of a packet network LAN (local area network) with common bridges and routers.
Recently announced broadband modems theoretically would seem to allow for expanded services on cable networks, encompassing bidirectional transfer of generalized voice and data communications between customer sites and head ends. It has been noted that it could take "at least five years " to "complete" what is characterized as the revolution required to produce suitable cable facilities. Although cable distribution networks in many areas have been upgraded from coaxial to fiber optic transmission lines, the latter having greater bandwidth capacities, the fiber optic is usually located between head ends and "neighborhood" distribution points, and coaxial cables still run between these points and customer premises. Thus, the bandwidth available for all transmissions is still that of coaxial cable; not optical fiber.
A presently recognized problem or obstacle, in respect to use of cable networks for telephony, is the need for "seamless" integration with existing telephony functions. To compete with the PSTN and Internet, an adaptation of cable networks to support telephony should allow for direct dialing of telephone calls in a manner fully consistent with existing direct dialing processes of the PSTN; so that users of cable telephone services would not require new telephone numbers, or use of digits in addition to their present PSTN telephone numbers, or contact with operators or representatives, for telephone activities that presently do not require such functions.
Another need presently recognized (at least by the present inventors) is that a competitive cable telephony service should include provision for maintaining at least emergency service during power outages. However, an obstacle to this is that cable networks cannot practically supply power to their "telephone" users the way telephone companies now do.
Our invention provides solutions to the foregoing problems and obstacles, by allowing for seamless and effective integration of telephone services into cable networks and/or other broadband networks.